Development of Self-Cleaning Box Culvert Design Phase II Sponsor: Iowa Highway Research Board Investigator: Dr. Marion Muste, The University of Iowa Presented By: Brian Worrel, Iowa DOT 2016 AASHTO RAC Meeting July 25-28 | Providence, Rhode Island

The Problem Obstructed culverts contribute to flooding and property damage. Cleanup is costly, time consuming and repetitive. Mechanics of sedimentation had not been well investigated. 2

Numerical Simulations Phase I – Sedimentation Mitigation Solution Phase I Goal: Hydraulically driven sedimentation mitigation. Minimum disturbance to natural stream ecology and habitat. Laboratory Modeling Numerical Simulations Mitigation Solution 3

Phase I - Sedimentation Mitigation Solution Main Channel Increased flow velocities Increased sediment transport capacity Side Barrels Enhanced turbulence Increased sediment suspension 4

Site Selection (11 Years Buildup) Phase II – Pilot Project Baseline Observation: No Mitigation Solution Site Selection (11 Years Buildup) First Project Cleanup Real Time Monitoring Two Years Buildup 5

Second Cleanup and Installation Phase II – Pilot Project Mitigation Solution Installed Product Selection Second Cleanup and Installation Real Time Monitoring 6

Phase II – Pilot Project Results After One Year Reliable and efficient in both testing and monitoring phases. Offers hydraulic and aquatic habitat similar to undisturbed stream. Simple to implement at any stage of the culvert lifetime. 7

Phase II – Pilot Project Current Status & Implementation Design guidance being developed through STIC. Web-based site selection application in development. Potential standard policy for triple box culverts. 8

? Determination of Value Costs Benefits Fillet Installation: $24k Cleanups Cleanup No Benefits Installation (+) Benefits ? Determination of Value Costs Fillet Installation: $24k Average Cleanup: $10k to $20k Benefits Fewer road closures Reduced maintenance costs Reduced property damage costs 9

Development of Self-Cleaning Box Culvert Design Phase II URL: publications.iowa.gov/16341 TRID Accession Number: 01518259 2016 AASHTO RAC Meeting July 25-28 | Providence, Rhode Island